Italian Party Flank Steak

Ingredients

• 1/4 cup olive oil
• 1/4 cup red-wine vinegar
• 2 coves of garlic, finely chopped
• 2 tablespoons chopped parsley
• 1/4 teaspoon coarse black pepper
• 1 flank steak (3/4 in thick, about 1 1/4 lbs), butterflied
• 2 red bell peppers
• 3 tablespoons chopped parsley
• 6 to 8 thin slices of prosciutto or other cured ham
• 24 medium sized fresh basil leaves
• 2 tablespoons grated parmesan cheese
• freshly ground pepper to taste
• 1 bunch watercress for garnish
• kitchen string